Cefditoren pivoxil, chemically known as (−)-(6R,7R)-2,2-dimethylpropionyloxymethyl 7-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-[(Z)-2-(4-methylthiazol-5-yl)ethenyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate, is an orally deliverable, third-generation cephalosporin. The empirical formula is C25H28N6O7S3 and the molecular weight is 620.73.
The chemical structure of cefditoren pivoxil is shown below:

Cefditoren pivoxil is a semi-synthetic cephalosporin antibiotic for oral administration. It is a prodrug which is hydrolyzed by gastro-intestinal esterases in the stomach and small intestine during absorption to form active cefditoren. Cefditoren is distributed in the circulating blood. The amorphous form of cefditoren pivoxil developed for clinical use is a light yellow powder. It is freely soluble in dilute hydrochloric acid and soluble at levels equal to 6.06 mg/mL in ethanol and <0.1 mg/mL in water.
Cefditoren pivoxil may be administered as part of a dosage form marketed by TAP Pharmaceuticals Inc. under the registered trademark name SPECTRACEF®. SPECTRACEF® tablets contain 200 mg of cefditoren as cefditoren pivoxil and inactive ingredients such as croscarmellose sodium, sodium caseinate (a milk protein), D-mannitol, magnesium stearate, sodium tripolyphosphate, hydroxypropyl methylcellulose, and hydroxypropyl cellulose. The tablet coating contains hydroxypropyl methylcellulose, titanium dioxide, polyethylene glycol, and carnauba wax. Tablets are printed with ink containing FD&C Blue No. 1, D&C Red No. 27, shellac, and propylene glycol.
Cefditoren pivoxil is indicated for the treatment of mild to moderate infections in humans caused by susceptible strains of certain microorganisms in conditions such as acute bacterial exacerbation of chronic bronchitis caused by Haemophilus influenzae (including (beta)-lactamase-producing strains), Haemophilus parainfluenzae (including (beta)-lactamase-producing strains), Streptococcus pneumoniae (penicillin-susceptible strains only), or Moraxella catarrhalis (including (beta)-lactamase-producing strains); community-acquired pneumonia caused by Haemophilus influenzae (including (beta)-lactamase-producing strains), Haemophilus parainfluenzae (including (beta)-lactamase-producing strains), Streptococcus pneumoniae (penicillin-susceptible strains only), or Moraxella catarrhalis (including (beta)-lactamase-producing strains); pharyngitis/tonsillitis caused by Streptococcus pyogenes; and uncomplicated skin and skin-structure infections caused by Staphylococcus aureus (including (beta)-lactamase-producing strains) or Streptococcus pyogenes. 
Cephalosporin compounds and their use have been described, for example, in U.S. Pat. No. 4,839,350 for “Cephalosporin Compounds and the Production Thereof,” U.S. Pat. No. 4,918,068 for “Cephem Compounds,” and U.S. Pat. No. 5,958,915 for “Antibacterial Composition for Oral Administration” which patents are hereby incorporated by reference.
Cefditoren exhibits poor bioavailability when taken orally and, as such, cefditoren pivoxil is generally prescribed to be taken with food to enhance absorption. Additionally, conventional cefditoren pivoxil tablets must generally be administered three times a day for the treatment of bacterial infections. The present invention addresses such problems by providing nanoparticulate compositions containing cefditoren, or a salt, derivative, prodrug, or other form thereof, for example cefditoren pivoxil, which overcome the poor bioavailability of cefditoren and eliminate the requirement to take the product with food. The present invention also provides a controlled release composition comprising cefditoren, or a salt, derivative, prodrug, or other form thereof, for example cefditoren picoxil, which eliminates the need to take cefditoren more than once a day, thereby increasing patient convenience and compliance.